UnitConversion.org
Perform online unit conversions for volume, distance, temperature, time, speed, and more for a total of 2,100 kinds of units in 78 different categories.
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Unit Converter
The converter works for units of area, energy, pressure, volume,
temperature, mass, length, numbers, velocity etc. You put in a number and
select a base unit and select a unit to convert to. The conversion result
will immediately appear in the output
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UnitMath - Paul M. Price
A calculation utility program for Mac or Windows, designed to answer questions written as equations made up of numbers, units (a unit is a quantity in terms of which the magnitudes of other quantities of the same type can be stated), precision, and operators.
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The Units of Measure C++ Library - Keith Nicewarner
The purpose of this library is to try to make it more difficult to make
coding mistakes that incorrectly mix units of measure. This is done with a
set of C++ classes that provide type-safe manipulation of units of measure
for various properties.
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Untangled - Mehta, Gayatri; Luo, Xiaozhong; et al.
Map and place logic blocks in this game to make more compact circuit layouts on a grid -- and more efficient computer chips. Visually appealing graphs bring nodes closer to parents or children and untangle knots in graphs; behind the scenes, the accumulated
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US2020
By organizing a million mentors from industry, this organization hopes to provide "uplifting moments of discovery to children through real-world, hands-on projects and academic coaching" in science, technology, engineering and math (STEM) fields. The
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USAMO/APMO/IMO/Putnam Archive - Kiran S. Kedlaya
Questions from some recent math competitions, in LaTeX or postscript format: the USA Mathematical Olympiad (USAMO) for high school students [1989-1999]; the Asian Pacific Mathematical Olympiad (APMO), a regional olympiad among countries on the Pacific
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U.S. Census Bureau
Information (searchable by keyword and browseable by subject) from summary data files across cities, towns, counties, states, and other geographic and demographic boundaries, useful for many purposes from allocating representation in legislative bodies
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Useless Facts about Pi - Paris
Facts "so useless not one of them has much bearing on pi's value": Euler's Relation; Irrationality (Niven's proof); Transcendence; Quadrature of the Circle with ruler and compass; The Content of n-Spheres.
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U.S. Energy Information Administration (EIA)
Links to facts/statistics on energy topics from A to Z: acid rain and air conditioning to world energy data on coal consumption, electricity prices, natural gas and oil consumption, and more. With tables, graphs, articles (some in PDF format), a Windows
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USolv-IT - Paul Igodt and Frank De Clerck
In Dutch or English: USolv-IT is a database containing thousands of mathematics/physics/statistics problems as an assessment tool. Part of the content is freely accessible via the web. A major part is for use by teachers in course contexts.
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